安溪县茶园小流域泥沙来源分析——以双岐溪为例

Sediment Source in a Small Scale Watershed of Tea Garden, a Case Study of the Shuangqi River, Anxi County

福建省茶园地处山丘地区加之缺乏水土保持措施,水土流失严重。指纹分析法利用泥沙特有的物理和生物化学性质作为示踪因子,用于区别不同泥沙来源地。本研究在安溪县山地茶园采集不同高程土壤样品及小流域中侵蚀泥沙样品,测定样品的8种土壤理化性质作为指纹识别因子,利用Kruskal-Wall检验筛选适合的指纹识别因子,运用组合指纹法与Isosource多元混合模型分析流域中侵蚀泥沙的来源及各潜在泥沙源地对侵蚀泥沙的贡献率。结果表明:茶园土壤中筛选出4种适用于山地茶园指纹因子:Ca、K、Zn、Mg,其中,K、Ca可作为判别泥沙来源的指纹因子组合。侵蚀泥沙超过70%来源于未治理茶园,且74%来源于未治理茶园山脚。组合指纹法在山地茶园的应用不仅能定量分析福建山地茶园水土流失、侵蚀泥沙的输移规律,进一步丰富了小流域侵蚀理论,也为茶园水土流失治理措施合理布设提供科学基础。

Serious water and soil erosion in the mountainous regions of tea garden is due to the lack of soil and water conservation measures in Fujian Province.The fingerprint technique by analyzing the physical and biochemical properties of sediment as tracers was used to distinguish sediment sources.The soil samples were collected at different elevation and sediment types from a small scale watershed in Anxi tea garden.The results showed that 4 factors(Ca,K,Zn,Mg)could be used as indices of composite fingerprint to distinguish the sediment source by using the Kruskal-Wall test and Isosource mixing model.Over 70%of sediment was derived from tea garden without soil and water conservation measures,especially,about 74%from the bottom of the tea garden.The composite fingerprint technique can quantitatively analyze soil and water loss in tea garden of hillslope in Fujian Province and understand transport characteristics of suspended sediment.Furthermore,this would enrich the erosion theory in small watershed and provide scientific basis for reasonable controlling soil erosion in tea garden.